Dynamic Path based on DropDownList

Can someone please explain to me how to dynamically set the path of the DirectAmazonUploader based on a DropDownList? I want the folder to be the text of the selected item of the dropdown, and once uploaded, to write the selectedvalue of the dropdown
to a SQL database.

So far I've been trying to set the Path in Page_PreRender to a Session variable that is populated on the SelectedIndexChanged event fires from the DropDownList (set to auto-postback). The weird behavior I get is that e.Path is always null inside the
ConfirmUpload event.